1. Field of the Invention
The present invention relates generally to conveyor systems. The present invention has a specific application to conveyor systems for sample analyzers such as chemical analyzers for testing characteristics of bodily fluids.
2. Related Art
Automated analyzers for chemical, immunochemical and/or biological testing of samples taken from patients are well known. Chemical or physical tests are performed on biological fluids such as urine, blood serum, plasma, cerebrospinal fluid and the like. A sample of the fluid is typically combined with a prepared reagent liquid, buffer liquid and/or diluting liquid and thereafter maintained at a controlled temperature until analytical measurements can be taken, such as by a photometer. For example, the measurement process analyzes the presence in the original sample of a given biochemical substance or characteristic.
There are several types of automatic sample analyzers. Preferably, each analyzer occupies a minimum of physical space, has a high throughput, analyzes dynamic as well as completed reactions and optimizes the placement of equipment. One type of analyzer has a plurality of parallel, simultaneously operating channels, each of which is arranged to accomplish a specific analysis. The analyses may be identical, to maximize throughput, or they may be distinct, to provide a variety of tests. A second type operates in series having one single processing channel for carrying out a specific analysis. Samples are supplied in sequence and analyzed sequentially according to the specific analysis assigned to the apparatus. In both of these types of systems, physical positioning of the various processing apparatus, such as sample load units, reagent add units, reagent mix units and sample unload units, is highly constrained for small systems. Such processing apparatus must be positioned relatively closely to one another so that each apparatus can accomplish its desired function at the proper time in the testing sequence. For large analyzers, processing apparatus, which might be spaced further apart physically from one another because of spacing requirements, often are too far away from the starting point for a sample to be processed within the required reaction or sensing time. Therefore, there are both close physical constraints and time restrictions on conventional sample analyzers. Limitations created by unique analysis procedures such as for dynamic reactions also restrict analyzer design and operation. These physical and time constraints lower sample throughput and inhibit the maximum use of mechanical equipment or the number of operations available in a given time period or step.
Accordingly, there is a need for a sample analyzer and process which increases sample throughput, which permits analysis of dynamic reactions and provides for multiple scans of a given sample, maximizes the use of processing apparatus and the number of operations occurring during the process, optimizes the residence time for a given sample in the system and which analyzes a large number of samples with a single analyzer. There is also a need for a sample analyzer which disassociates physical and temporal space, e.g. which separates the logical processing steps from the physical limitations of a given system, thereby allowing discrete processing apparatus to be spaced out over the architecture of the system and so that the processing apparatus can still conform to the spacial and timing requirements for the analyzer.
It is an object, therefore, of the present invention to provide a system and apparatus for efficiently, in terms of both time and space, transporting samples or other items for processing, which provides a high throughput, which maximizes the use and positioning of processing apparatus, which maximizes the number of operations occurring in a given amount of time and which optimizes the residence times of and analysis steps for the samples or other items. It is a further object of the present invention to disassociate logical and physical space with respect to the samples or other items being analyzed and with respect to the processing apparatus, and to permit operation on a large number of samples or items with a single processing apparatus. It is also an object of the present invention to provide a sample analyzer which moves samples a plurality of times and which can perform an operation such as scanning for all samples every time the samples are moved. It is an additional object to provide a sample analyzer which can track blank sample areas for calibration or other processing.